An NCI Working Group on Epidemiologic Data Resources was established in 1978 by the Director, NCI, with Dr. Beebe as chairman. Its charge was to identify and develop new data resources and to protect existing ones. The Working Group has occupied itself with a wide variety of tasks: promotion of computerized record linkage, development of a national database for occupational mortality, obtaining and retaining access to administrative files of Federal agencies, seeking new databases, providing oversight on the use of the hospital discharge database of the Veterans' Administration hospital system, advising the National Center for Health Statistics on its National Death Index, and reviewing all Master Order Agreement-Requests for Proposals. It has also been trying to promote a legislative initiative that would broaden access to the address file of the Internal Revenue Service beyond its present scope that is limited to occupational studies and studies of war veterans.